package MAIN;

import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main3 {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        String str = in.nextLine();
        String solStr = solution(str);
        System.out.println(solStr);
    }
    
    private static String solution(String str) {
        int first = 0;
        int last = first +1;
        while (last < str.length()) {
            char cf = str.charAt(first);
            char cl = str.charAt(last);
            if ((cf-cl) == 0) {//相同，需要消除
                str.replaceFirst(cf + "","");
            }
            last++;
        }
        return str;
    }
}